Jay-Z has to explain who he is to an old woman on the subway - watch

He may be one of the most famous rappers on the planet, but Jay-Z still had to explain who he was to an older lady while catching the subway to one of his New York gigs - scroll down to the bottom of the page and click to watch.

The clip is taken from the rapper's new documentary Life + Times, in which he chronicles his involvement with the US venue the Barclays Centre, where he played an eight-show residency earlier this year. On his way to the final show (October 6), he sparked excitement amongst fellow commuters when he hopped on a Brooklyn-bound R train at the MTA station in Canal Street at around 6pm and rode it all the way to the venue.

While other travellers took to Twitter to express their shock at seeing the hip-hop artist using public transport, another passenger - named Ellen - seemed nonplussed. "Are you famous?", she asked, prompting Jay-Z to respond: "Yes. Not very famous, you don't know me... but I'll get there some day."

When he told her he was en route to perform at the new venue, meanwhile, she replied: "Oh, fabulous!" and told him she was "proud" of him for using public transport. By the end of the conversation, however, she is seemingly aware of Jay-Z's status. "Oh, you're Jay-Z!" she said. "I know about Jay-Z."

The documentary has been released to coincide with Jay-Z's birthday, as the rapper turned 43 yesterday (December 4). You can watch the whole 24-minute film at the bottom of the page.

Not to be outdone by her husband, Jay-Z's wife Beyonce has also recently announced plans for a documentary. The self-directed movie is said to include unreleased and behind-the-scenes footage of Beyonce, as well as live performance footage. A trailer for the film, which will be streamed by US broadcaster HBO in February 2013, hit the web earlier this week - click below to see the clip.